Dorothy Adams
— Dr. Trykel's Associate
Morris Ankrum
— Narrator (voice)
Ralph Dunn
— Detective Lester
Harry Hayden
— Gus Conklin
Lloyd Ingraham
— High School Principal
Howard M. Mitchell
— Butcher
Frank Reicher
— Philip Kenneson, Sr.
Arthur Shields
— Dr. Rupert Trykel
Ann Shoemaker
— Mrs. Martha Kenneson
Crane Whitley
— Inspector Becker